Breakaway speed. How fast is the plane flying?

Otherwise, the rate of climb. Depends on the model and the glide path (trajectory) specified by the dispatcher, depending on flight conditions. On average, a jet airliner gains an altitude of one kilometer in about a minute (about 15 m/s), and the rules of use airspace The Russian Federation states that this value should be “...10 m/s or more.” If you're wondering how high it can go passenger airliner– We suggest you read this article.

Features of military aircraft

Fighters, attack aircraft, and interceptors do not always take off from the runway. Their takeoff conditions are often extreme. For example, it can occur from the deck of a ship, where it is not possible to accelerate to the required speed.

Therefore, the military often uses additional devices, namely:

An ejection device that launches an aircraft and gives it acceleration. When landing in a confined space, hooks are used, with which the devices cling to a steel brake cable stretched across the deck.
Additional devices that create vertical traction. For example, these could be fan-type devices that create a powerful directed counter-movement of air above the deck. The consequence of this is lifting force.
Note: the same air flow is used for landing.

The video demonstrates the takeoff and landing process through the eyes of the pilots.

The flight of a colossus weighing several tens or hundreds of tons is a complex process. It depends on many factors and is determined by the speed of the aircraft. The greater the mass and the more complex the conditions, the greater the speed required for liftoff and movement. In particularly difficult conditions, auxiliary mechanisms are used. Maintaining speed is one of the factors of safe flight.

The question of what speed a plane develops during takeoff interests many passengers. The opinions of non-professionals always differ - some mistakenly assume that the speed is always the same for all types of a given aircraft, others correctly believe that it is different, but cannot explain why. Let's try to understand this topic.

Takeoff

Takeoff is a process that occupies a time scale from the beginning of the aircraft's movement until it completely lifts off the runway. Takeoff is possible only if one condition is met: the lifting force must acquire a value greater than the mass of the object taking off.

Types of takeoff

Various “interfering” factors that have to be overcome to get the plane into the air ( weather, wind direction, limited runway, limited engine power, etc.), prompted aircraft designers to create many ways to circumvent them. Not only the design of flying vehicles has improved, but also the process of their takeoff. Thus, several types of takeoff were developed:

Off the brakes. Acceleration of the aircraft begins only after the engines reach the set thrust mode, and until then the aircraft is held in place using the brakes;
A simple classic take-off, which involves a gradual increase in engine thrust as the aircraft moves along the runway;
Take-off using aids. Typical for aircraft performing combat service on aircraft carriers. The limited runway distance is compensated by the use of ski-jumps, ejection devices, or even additional rocket engines installed on the aircraft;
Vertical take-off. Possible if the aircraft has engines with vertical thrust (for example, the domestic Yak-38). Such devices, similar to helicopters, first gain altitude from a standing position vertically or when accelerating from a very short distance, and then smoothly transition to horizontal flight.

Let's take the takeoff phase as an example. jet plane Boeing 737.

Boeing 737-800 take off

Takeoff of a passenger Boeing 737

Almost every civil jet aircraft takes off according to the classical scheme, i.e. the engine gains the required thrust directly during the take-off process. It looks like this:

The aircraft begins to move after the engine reaches about 800 rpm. The pilot gradually releases the brakes while keeping the control stick neutral. The run begins on three wheels;
To begin lifting off the ground, the Boeing must acquire a speed of about 180 km/h. When this value is reached, the pilot smoothly pulls the handle, which leads to the deflection of the flaps and, as a consequence, the raising of the nose of the device. Then the plane accelerates on two wheels;
With its nose raised on two wheels, the plane continues to accelerate until the speed reaches 220 km/h. When this value is reached, the plane takes off from the ground.

Takeoff speed of other standard aircraft

Airbus A380 – 269 km/h;
Boeing 747 – 270 km/h;
Il 96 – 250 km/h;
Tu 154M – 210 km/h;
Yak 40 – 180 km/h.

The given speed is not always enough for take-off. In situations where strong winds blow in the direction of the aircraft's takeoff, higher ground speed is required. Or, conversely, in a headwind, a lower speed is sufficient.

Based on materials from techcult

Takeoff

Take-off is a process that spans the time scale from the start of the aircraft's movement to its complete lift-off from the runway. Takeoff is possible only if one condition is met: the lift force must acquire a value greater than the mass of the object taking off.

Types of takeoff

Various “interfering” factors that have to be overcome to get an airplane into the air (weather conditions, wind direction, limited runway, limited engine power, etc.) have prompted aircraft designers to create many ways to circumvent them. Not only the design of flying vehicles has improved, but also the process of their takeoff. Thus, several types of takeoff were developed:

Off the brakes. Acceleration of the aircraft begins only after the engines reach the set thrust mode, and until then the aircraft is held in place using the brakes;
A simple classic takeoff, which involves a gradual increase in engine thrust while the aircraft is moving along runway;
Take-off using aids. Typical for aircraft performing combat service on aircraft carriers. The limited runway distance is compensated by the use of ski-jumps, ejection devices, or even additional rocket engines installed on the aircraft;
Vertical take-off. Possible if the aircraft has engines with vertical thrust (for example, the domestic Yak-38). Such devices, similar to helicopters, first gain altitude from a standing position vertically or when accelerating from a very short distance, and then smoothly transition to horizontal flight.

Consider, as an example, the takeoff phases of a Boeing 737 turbofan aircraft.

Takeoff of a passenger Boeing 737

Almost every civil aircraft takes off according to the classical scheme, i.e. the engine gains the required thrust directly during the takeoff process. It looks like this:

The aircraft begins to move after the engine reaches about 800 rpm. The pilot gradually releases the brakes while keeping the control stick neutral. The run starts on three wheels;
To begin lifting off the ground, the Boeing must acquire a speed of about 180 km/h. When this value is reached, the pilot smoothly pulls the handle, which leads to the deflection of the flaps and, as a consequence, the raising of the nose of the device. Then the plane accelerates on two wheels;
With its nose raised and on two wheels, the aircraft continues to accelerate until the speed reaches 220 km/h. When this value is reached, the aircraft takes off from the ground.

IN technical characteristics Oh aircraft everything is important. After all, the viability of the liners and the safety of the people on board literally depend on every little detail. However, there are parameters that can be called basic. This, for example, is the takeoff and landing speed of an aircraft.

For the operation of aircraft and their operation, it is extremely important to know what exactly the speed of the aircraft can be during takeoff, namely at the moment when it takes off from the ground. This parameter will be different for different airliner models: for heavier aircraft the indicators are higher, for lighter aircraft the indicators are lower.

Takeoff speed is important because the designers and engineers involved in the manufacture and calculation of all the characteristics of the aircraft need this data to understand how much lift the lift will produce.

IN different models There are different parameters for take-off run and take-off speed. For example, the Airbus A380, which today is considered one of the most modern aircraft, accelerates on the runway to 268 km per hour. For a Boeing 747, this would require a takeoff run of 270 km per hour. The Russian representative of the aviation industry Il 96 has takeoff speed 250 km per hour. For Tu 154 it is 210 km per hour.

But these numbers are presented as averages. After all, the final acceleration speed of the airliner along the runway is influenced by a number of factors, including:

Wind speed
Direction of the wind
Runway length
Atmosphere pressure
Humidity of air masses
Runway condition

All this has an effect and can either slow down the plane or give it a slight acceleration.

How exactly does takeoff happen?

As experts note, the aerodynamics of any airliner is characterized by the configuration of the aircraft’s wings. As a rule, it is standard and the same for different types of aircraft - the lower part of the wing will always be flat, the upper part will be convex. The difference is only in small details, and does not depend on the type of aircraft.

The air passing under the wing does not change its properties. But the air that ends up on top begins to narrow. This means that less air passes from above. This ratio causes a pressure difference around the wings of the airliner. And it is precisely this that forms the very lifting force that pushes the wing upward, and with it lifts the plane.

The aircraft lifts off the ground at the moment when the lifting force begins to exceed the weight of the aircraft itself. And this can only happen with an increase in the speed of the aircraft itself - the higher it is, the greater the pressure difference around the wings increases.

The pilot has the opportunity to work with lift - for this, flaps are provided in the wing configuration. So, if he lowers them, they will change the lift vector to a sharp climb mode.

The smooth flight of the airliner is ensured when a balance is maintained between the weight of the airliner and the lifting force.

What types of takeoff are there?

For overclocking passenger plane pilots are required to select a special engine operating mode called takeoff. It only lasts a few minutes. But there are exceptions, when there is some kind of locality, the plane in this case can take off as usual, which allows reducing the noise load, because at takeoff mode The plane's engines roar very loudly.

Experts distinguish two types of takeoff of passenger airliners:

take-off with brakes: this means that at first the plane is held on the brakes, the engines switch to maximum thrust mode, after which the airliner is released from the brakes and the takeoff begins
Takeoff with a short stop on the runway: in such a situation, the airliner begins to run along the runway immediately without any prior adjustment of the engines to the required mode. Afterwards the speed increases and reaches the required hundreds of kilometers per hour

Landing nuances

By landing, pilots understand the final stage of the flight, which is the descent from the sky to the ground, the slowing down of the airliner and its complete stop on the runway at the airport. The plane's descent begins at 25 meters. And in fact, landing in the air takes only a few seconds.

When landing, pilots face a whole range of tasks, because... It actually happens in 4 different stages:

Leveling - in this case, the vertical rate of descent of the liner goes to zero. This stage starts 8-10 meters above the ground and ends at 1 meter
Holding: in this case, the speed of the airliner continues to decrease, and the descent remains smooth and ongoing
Parachuting: at this stage there is a decrease in the lift of the wings and an increase in the vertical speed of the aircraft
Landing: this refers to direct contact with a hard surface of the chassis

It is during the landing stage that pilots record the landing speed of the aircraft. Again, the speed varies depending on the model. For example, for a Boeing 737 it will be 250-270 km per hour. The Airbus A380 lands with the same parameters. If the plane is smaller and lighter, 200 km per hour will be enough for it.

It is important to understand that landing speed is directly affected by exactly the same factors that affect takeoff.

The time intervals here are very small, and the speeds are enormous, which becomes the cause of the most frequent disasters precisely at these stages. After all, pilots have very little time to make strategically important decisions, and every mistake can be fatal. Therefore, a lot of time is devoted to practicing landing and takeoff during pilot training.

IN passenger aviation The flight altitude is determined by the technical capabilities of the aircraft and established rules. The height can be maximum and ideal. The choice of altitude does not depend on the decision of the commander; he is limited in his actions by ground services.

Why 10 thousand?

The liner reaches the ideal ten kilometers in 20 minutes. If the flight does not exceed half an hour, such a need does not arise. The decision whether to maintain the corridor or go up another one to two thousand depends on the situation. The higher the aircraft rises, the thinner the atmosphere becomes. It creates less drag, which reduces the amount of fuel burned to overcome it. In the atmosphere at an altitude of 10 thousand, the amount of oxygen necessary to ensure the combustion process of kerosene is retained. Birds do not fly at this altitude; a collision with them will cause an accident.

The decision on flight altitude is made by ground control services.

They give commands to pilots based on objective factors:

weather;
wind speed at the surface of the earth;
vessel weight and technical characteristics;
flight time and distance;
direction: west or east.

The selected altitude is defined in flight rules as flight level. Air law defines uniform flight levels for the airspace of all countries. If the ship is flying east, the dispatcher has the right to choose odd levels of 35, 37, 39 thousand pounds ( from 10 to 12 kilometers). For aircraft traveling in the opposite direction, even flight levels are offered. This is 30, 36, 40 thousand pounds above sea level ( from 9 to 11 kilometers). This tactic is aimed at avoiding collisions. The flight level is calculated before the vehicle takes off.

Affects height and range of flight, on small routes, gaining altitude is impractical. The ship's commander determines the altitude using a barometer installed on board.

This video explains why planes fly:

Maximum height

The maximum altitude is directly related to the maximum speed. At a speed of 950-1000 kilometers per hour, the altitude reaches 10 kilometers. For small private jets the ratio will be 300 km per hour and 2000 thousand meters.

It is not only the aircraft model that determines its maximum possible altitude, but also the physical characteristics of the atmosphere. Aircraft specifications are different for passenger and military air transport vehicles.

The maximum height is determined by:

technical characteristics are engine power and wing lift;
make and type of vessel;
aircraft weight.

The Russian TU-204 can reach an altitude of no more than 7200 meters. The IL-62 will rise 11 kilometers, the same amount as the Airbus A310. The newest Irkut MS-21, which first took to the skies on May 28, 2017, will be able to gain 11.5 kilometers due to its low mass. The leader among new products in the industry, the Sukhoi Superjet SSJ 100SV, already rises to 12,200 meters.

Before Sukhoi’s development entered the market, only Boeing managed to exceed the 12 thousand limit.

There are altitude limits related to the amount of oxygen in the atmosphere. They depend on the type of engine. An airplane with a turbojet engine can reach 32 thousand meters; for a ramjet airplane the limit will be higher, it will be 45 thousand meters.

The maximum altitude of a turbojet military vessel can exceed 35 thousand meters; the Russian MIG-25 managed to reach it.

Watch a video about how Mig 25 rises into the stratosphere

Ideal height

The definition refers to the same altitude in the range of 10-12 thousand meters, where the ideal air flow density is observed. They are sufficiently discharged to reduce the friction of the sides with the air and fuel consumption. Their density remains sufficient to support the wings of the aircraft. When entering the stratosphere, the level of support drops and the aircraft begins to “collapse.”

Taking these parameters into account, the pilots developed a definition of the “ideal” corridor. Coming down from it increases fuel consumption, the economic efficiency of the flight decreases along with its altitude, so in any situation the pilot would rather increase the altitude than reduce it.

Within the allocated flight level, the pilot himself makes the decision on altitude, taking into account the current ratio of friction and support, taking into account the technical characteristics of the vessel. Often the change in altitude is associated with turbulence, but it is also coordinated with ground services. Clouds are more often overcome when rising above their level, and the closure of space over the region due to military operations or mountain peaks can also cause a change in height.

Remember. Changing flight levels is possible only when leaving the route at a distance of 20 kilometers and in agreement with ground services.

How tall are Boeing 747 and 737?

Models of the American corporation also fly on Russian flights. Among wide-body passenger aircraft it is most often used by airlines due to the cost-effectiveness of mass transportation. Five Boeing 747s belong to Rossiya Airlines. The maximum speed of the vessel is 988 km per hour for the 747-8 modification, maximum height the height he can climb is 13,700 meters.

Boeing 737 gains a lower altitude, the ceiling is 12,500 meters for the 737-800 model and 11,300 meters for the Boeing 737-500. The ability to reach such an altitude ensures fuel efficiency of flights. The designers envision the release of the Boeing 737 MAX 8, which should further improve these characteristics.

In aviation, the optimal heights of air corridors for all types of aircraft have been calculated. Pilots must adhere to the instructions of air traffic control services, retaining freedom of maneuver and the right to make independent decisions in a critical situation. The safety of the airspace depends on the coordinated actions of the crew and ground controllers in choosing the maximum altitude.